1. Field of the Invention
This invention relates generally to the field of semiconductor device manufacturing and, more particularly, to a fault detection control system using dual bus architecture, and methods of using same.
2. Description of the Related Art
There is a constant drive within the semiconductor industry to increase the quality, reliability and throughput of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably. These demands have resulted in a continual improvement in the manufacture of semiconductor devices, e.g., transistors, as well as in the manufacture of integrated circuit devices incorporating such transistors. Additionally, reducing the defects in the manufacture of the components of a typical transistor also lowers the overall cost per transistor as well as the cost of integrated circuit devices incorporating such transistors.
Generally, a set of processing steps is performed on a lot of wafers using a variety of processing tools, including photolithography steppers, etch tools, deposition tools, polishing tools, rapid thermal processing tools, implantation tools, etc. The technologies underlying semiconductor processing tools have attracted increased attention over the last several years, resulting in substantial refinements. However, despite the advances made in this area, many of the processing tools that are currently commercially available suffer certain deficiencies. In particular, such tools often lack advanced process data monitoring capabilities, such as the ability to provide historical parametric data in a user-friendly format, as well as event logging, real-time graphical display of both current processing parameters and the processing parameters of the entire run, and remote, i.e., local site and worldwide, monitoring. These deficiencies can engender non-optimal control of critical processing parameters, such as throughput, accuracy, stability and repeatability, processing temperatures, mechanical tool parameters, and the like. This variability manifests itself as within-run disparities, run-to-run disparities and tool-to-tool disparities that can propagate into deviations in product quality and performance, whereas an ideal monitoring and diagnostics system for such tools would provide a means of monitoring this variability, as well as provide means for optimizing control of critical parameters.
One technique for improving the operation of a semiconductor processing line includes using a factory wide control system to automatically control the operation of the various processing tools. The manufacturing tools communicate with a manufacturing framework or a network of processing modules. Each manufacturing tool is generally connected to an equipment interface. The equipment interface is connected to a machine interface which facilitates communications between the manufacturing tool and the manufacturing framework. The machine interface can generally be part of an advanced process control (APC) system. The APC system initiates a control script based upon a manufacturing model, which can be a software program that automatically retrieves the data needed to execute a manufacturing process. Often, semiconductor devices are staged through multiple manufacturing tools for multiple processes, generating data relating to the quality of the processed semiconductor devices. Typically, the manufacturing tools operate in accordance with predetermined scripts, or recipes. Some tools include internal monitoring systems that report various events, including errors, to a tool operator. Typically, these reported events are displayed on a printer or a display screen and/or are written to a data file.
The various processes performed in manufacturing integrated circuit devices, e.g., etching processes, deposition processes, ion implant processes, etc., are very complex and, in some cases, very difficult to control to the precise level required to manufacture today""s integrated circuit products. Accordingly, such processes are monitored frequently, if not continuously, using various sensors or other metrology tools in an effort to insure that the process produces acceptable results. As a result of this monitoring, enormous volumes of data are collected, stored in one or more databases, and ultimately analyzed in an effort to obtain a better control of the various processes used to form the integrated circuit products. Typically, this data is provided to, or made available to, an overall manufacturing execution system (MES) that is responsible for, in general, management and control of many aspects of a semiconductor manufacturing facility. In some cases, the MES system also provides some form of fault detection analysis of the various processes used in forming the integrated circuit products. Typically, the fault detection involves analysis of some or all of the very large volume of data collected by the various sensors and metrology tools or devices. Unfortunately, performing fault detection analysis in this manner often results in an unacceptably slow response, given the large volume of data that is typically retrieved from a database, and cumbersome fault detection methodologies may result in reduced yields in semiconductor manufacturing operations and an overall decrease in manufacturing efficiencies.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
The present invention is generally directed to a fault detection control system using dual bus architecture, and methods of using same. In one illustrative embodiment, the system comprises a plurality of process tools, each of the tools adapted to perform at least one process operation on at least one workpiece, at least one sensor that is operatively coupled to each of the process tools and adapted to sense at least one parameter associated with at least one process operation, an initial fault detection unit coupled to an instrument bus, the initial fault detection unit adapted to receive data from at least one sensor on each of the plurality of process tools via the instrument bus, and a primary fault detection unit operatively coupled to a manufacturing execution system and a system bus, the data from the sensors on each of the plurality of process tools being provided to the primary fault detection unit after the data is processed in the initial fault detection unit.
In one illustrative embodiment, a method of identifying faults in a manufacturing system comprises processing a workpiece in a process tool, obtaining data regarding the processing of the workpiece in the process tool via at least one sensor that is operatively coupled to the process tool, providing the data obtained by the at least one sensor to an initial fault detection unit that is adapted to receive the data via an instrument bus, the initial fault detection unit determining if an alarm condition exists, and providing the data to a primary fault detection control unit via a system bus after the data is processed through the initial fault detection unit. In some cases, an alarm condition may be indicated if the data falls outside of a preselected acceptable range or exceeds an allowable value.